Why the fuck someone would stop being friend of someone else because that person is dying? Unless is from a zombie plague there is no excuse man. I dont joke when I say lots of you here are considered friends by me.
Stress, mostly. Least from what I've seen in my life. Like, I haven't
done it, but there's been days I've very seriously considered just fucking off to the other end of the country and leaving my grandparents (different situations, being old age and dementia and me the primary caretaker instead of just a friend, but still, their clock is very clearly ticking down) behind for other people to deal with, because trying to handle everything involved is pretty literally killing me (started blood pressure medication last night, haha!).
Sometimes when all the shit piles up and you don't really know what the fuck to do, folks will cut ties with what they're troubled by instead of figuring out other ways to deal with it, even if it means basically leaving a friend in a ditch. It sucks and it's generally a pretty shitty thing to do, but, like... I get it, y'know? I understand how someone can do it. When you're buried by everything else and got the extra shit sandwich of having friends or family die on you it's really fucking tempting to just... not. You'd probably feel a bit bad in some ways but in others it'd be such a goddamn
relief, out of sight and out of mind, etc.